0.1.0 


#33 in #arbitraryprecision
190KB
4.5K
SLoC
Reckoner
A high level arbitrary precision integer and rational arithmetic library wrapping imath
.
Example
The following example computes an approximation of pi using the Newton / Euler Convergence Transformation.
use reckoner::{Integer, Rational};
fn factorial(v: &Integer) > Integer {
let mut accum = 1.into();
let mut f = v.clone();
while f > 0 {
accum *= &f;
f = 1;
}
accum
}
// Product of all odd integer up to the given value.
fn odd_factorial(v: &Integer) > Integer {
let mut accum = 1.into();
let mut f = if v % 2 == 0 { v  1 } else { v.clone() };
while f > 0 {
accum *= &f;
f = 2;
}
accum
}
// ```
// \frac{\pi}{2}
// = \sum_{k=0}^\infty\frac{k!}{(2k+1)!!}
// = \sum_{k=0}^{\infty} \cfrac {2^k k!^2}{(2k + 1)!}
// = 1+\frac{1}{3}\left(1+\frac{2}{5}\left(1+\frac{3}{7}\left(1+\cdots\right)\right)\right)
// ```
fn compute_pi_approx(iterations: u32) > Rational {
2 * (0..iterations)
.map(Integer::from)
.map(n {
let numerator = factorial(&n);
let denominator = odd_factorial(&(2 * n + 1));
(numerator, denominator).into()
})
.sum::<Rational>()
}
See examples/
for more.
Crates
The MSRV for both crates is 1.64.0
.
reckoner
A high level arbitrary precision arithmetic library supporting integer and rational numbers.
creachadairimathsys
FFI bindings for imath
.
Documentation
Dependencies
~0–1.8MB
~35K SLoC